Is this a Rorschach test? A paint spill? A well-used artist’s palette? It’s actually a U.S. Geological Survey topographical map of a crater — specifically, a “multiple-layered ejecta crater” — on the surface of Mars. Martian craters like the one mapped here are shaped by the effects of impacts into ice-rich ground. By mapping this crater, scientists learned that the massive projectile that caused the impact penetrated through the icy planet’s surface into the rocky layer beneath at a horizontal angle. The radiating patterns represented by the colors on this map artfully trace the shock waves which left their marks on the planet’s surface.